1. Field of the Invention
The invention relates to a color wheel assembly, more particularly to a color wheel assembly that can prevent undesirable overflow of adhesive during assembly and that can permit easy adjustment of rotational imbalance.
2. Description of the Related Art
Referring to FIG. 1, a conventional color wheel assembly, as disclosed in U.S. Pat. No. 5,868,482, is shown to include a motor 1, a carrier 2 mounted on a shaft of the motor 1, an adhesive layer 3 coated on the carrier 2, three sector-shaped filter segments 4 that are adhered to the adhesive layer 3 and that are combined to form a ring shape, and a ring member 5 that covers a bonding area of the filter segments 4 on the carrier 2. When the motor 1 drives the carrier 2 and the filter segments 4 to rotate at a high speed, light beams projected from a light source (not shown) can pass through the filter segments 4 so as to produce an image on a screen (not shown).
Although the conventional color wheel assembly can achieve its intended purpose, it has the following drawbacks:
1. To compensate for imbalance, the conventional color wheel assembly is provided with a balancing hole 201 in the carrier 2. However, boring of the balancing hole 201 is difficult since a proper force has to be exerted so that damage to the bearing of the motor 1 that supports the carrier 2 does not occur. Further, metal shavings produced during boring of the balancing hole 201 have a tendency to disperse and thereby cause damage to coated surfaces of the filter segments 4.
2. Since the filter segments 4 are adhered together to the carrier 2 during assembly, when one of the filter segments 4 is damaged or defective, the whole conventional color wheel assembly has to be discarded since the conventional color wheel assembly does not permit partial replacement of component parts. As a result, not only are the components wasted, but overall production costs are indirectly increased.
Referring to FIGS. 2 and 3, another conventional color wheel assembly, as disclosed in U.S. Pat. No. 6,715,887, is shown to include a motor 6, a carrier 7 mounted on a shaft of the motor 6 and having an annular groove 701, a plurality of sector-shaped filter segments 8, and a packing ring 9 fitted into the annular groove 701. During assembly, the packing ring 9 is first adhered to the filter segments 8 so as to form one body, after which balancing is performed. Finally, the packing ring 9 is fitted into the annular groove 701.
Although any imbalance in the conventional color wheel assembly can be minimized, the conventional color wheel assembly has the following drawbacks:
1. When a top surface of the packing ring 9 is adhered to bottom surfaces of the filter segments 8, excess adhesive is likely to back up onto the bottom surfaces of the filter segments 8. This results in interference with light beams projected from a light source (not shown).
2. This conventional color wheel assembly also does not permit partial replacement of component parts since the filter segments 8 are adhered fixedly to the packing ring 9. Hence, when one of the filter segments 8 is damaged or defective, the whole assembly of the filter segments 8 and the packing ring 9 has to be replaced.
3. Imbalance may still occur due to the motor 6 after assembly. However, correction of imbalance after assembly is difficult.